When we've knocked the Gen Battery question around here a while back, the # I retained was 5 years... interesting that the GoogleMonster knocks it down even further.....
Crazy that you are seeing that 10-2 variation grs; that could be some of what drives Google's low #....
When a retired Eng buddy of mine (Northern Canada) built his retirement home, he did the research on Generac's specs @ the time, and realized that he needed/wanted a higher pressure regulator for Natgas (than standard residential) for the gen to deliver max output @ typical worst case Winter temperatures.
So, he got the gas company to install the higher pressure regulator for the gen, and being who he is, bought a 2nd high pressure regulator to have on the shelf, as it wasn't something the gas company stocked locally. At first the gas co wanted to install 2 meters (never dealt with this in Residential before), but IIRC, it ended up being 1 meter, with 2 regulators in the end.
So, of course, Murph will leave him alone, and that original regulator will probably run fine right up until he no longer has a need for the house !
Esp. since it is grs-reviewed, if you haven't already daugen, you might want to post that Google list over in the AI Being Helpful thread that scootr started..... many people (who don't hang out here) might find that 3 year # informative/startling....
Rgds, D.